Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
  • C09J183/06—Polysiloxanes containing silicon bound to oxygen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
  • C09J183/08—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen

Definitions

• the invention relates to an electrically insulating adhesive, a method for its production and its use for the production of electrically insulating bonds.
• a large number of organic adhesives are known for bonding inorganic materials (substrates) to the same or organic substrates, but the basis for connection to the organic material is only the physical "push-button principle".
• alkoxysilanes are also used as adhesion promoters / adhesives, which bind to the oxidic surface of the inorganic substrate via silanol groups.
• the disadvantage here is that complex multi-layer technology is required when using primer and adhesive, or outgassing of the alcohol formed under stress conditions of the substrates to be bonded is to be expected if only the adhesion promoter is used.
• the object of the invention was to provide storage-stable and electrically insulating adhesives which can be used for producing electrically insulating bonds.
• the bonded substrates should be electrically insulated.
• the adhesive should enable an excellent connection to inorganic substrate materials, i.e. it should adhere well to inorganic substrate materials and be easy and quick to use,
• the proportion of component a) of the general formula I is between 2 and 6 mol%
• the proportion of component b) of the general formula II is between 69 and 83 mol%
• the proportion of component c) of the general formula III is between 15 and 25 mol%.
• the alkyl residues are e.g. straight-chain, branched or cyclic radicals with 1 to 20, in particular with 1 to 10 carbon atoms and preferably lower alkyl radicals with 1 to 6, particularly preferably with 1 to 4, carbon atoms.
• Specific examples are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, dodecyl and octadecyl.
• alkenyl residues are e.g. straight-chain, branched or cyclic residues with 2 to 20, preferably with 2 to 10 carbon atoms and preferably lower alkenyl residues with 2 to 6 carbon atoms, such as e.g. Vinyl, allyl and 2-butenyl.
• Preferred aryl radicals are phenyl, biphenyl and naphthyl.
• the alkoxy, acyloxy, alkylamino, dialkylamino, alkylcarbonyl, alkoxycarbonyl, arylalkyl, alkylaryl, alkylene and alkylenearylene radicals are preferably derived from the above-mentioned alkyl and aryl radicals.
• the radicals mentioned can optionally carry one or more substituents, for example halogen, alkyl, hydroxyalkyl, alkoxy, aryl, aryloxy, alkylcarbonyl, alkoxycarbonyl, furfuryl, tetrahydrofurfuryl, amino, monoalkylamino, dialkylamino, trialkylammonium, amido, hydroxy, formyl, carboxy, mercapto, Cyano, isocyanato, nitro, epoxy, SO 3 H or PO 4 H 2 .
• halogens fluorine, chlorine and bromine and especially chlorine are preferred.
• silanes of the general formula I, II and III can be hydrolyzed and condensed via the radicals R and X.
• An inorganic network with Si-O-Si units can be built up via these hydrolyzable groups, while in the rest Y polymerize the polymerizable groups contained in the general formula II to build up an organic network.
• Silanes of the general formula I have only hydrolyzable radicals and thus exercise the function of an inorganic network former. Without restricting generality, there are concrete examples of silanes of the general formula I SiCl 4 , HSiCl 3 , Si (OCH 3 ) 4 , Si (OOCH 3 ) 4 and Si (OC 2 H 5 ) 4 , where Si (OC 2 H 5 ) 4 (TEOS) is preferred.
• Silanes of the general formula II have polymerizable radicals Y and thus exercise the function of an organic network former. It is preferred if component b) of the general formula II R ''YSiX 3 is, with R '''being alkylene with 1 to 4 C atoms, Y being acryloxy, methacryloxy, glycidyloxy, allyl, vinyl or epoxycyclohexyl and X being alkoxy having 1 to 4 C atoms.
• component b) of the general formula II is 3-glycidyloxypropyltrimethoxysilane and / or 3-methacryloxypropyltrimethoxysilane.
• Silanes of the general formula III have both hydrolyzable radicals X and non-hydrolyzable radicals R ′′ and have the function of a network converter. It is preferred if component c) of the general formula III has the formula R '' 2 SiX 2 has, with R '' equal to aryl and X equal to hydroxy or alkoxy with 1 to 4 carbon atoms.
• a particularly preferred network converter is (HO) 2 Si (C 6 H 5 ) 2 .
• Organically modified silanes of the general formulas I, II and III are either commercially available or can be prepared by methods as described in "Chemistry and Technology of Silicones" (W. Noll, Verlag Chemie, Weinheim / Bergstrasse, 1968). Attention should be paid to the purity of the silanes used, since traces of electrolytes, such as Cl - , B 3+ -, Ca 2+ - or Ti 4+ ions, can adversely change the electrical properties of the adhesive.
• the silanes of the general formulas I, II and III can be used either as such or in precondensed form.
• the silanes of the general formulas I, II and III are hydrolyzed and polycondensed.
• the polycondensation is preferably carried out according to the sol-gel process, as is e.g. is described in DE-A1 2758414, 2758415, 3011761, 3826715 and 3835968.
• the hydrolytic condensation can e.g. by adding the required water at room temperature or with gentle cooling (preferably with stirring and in the presence of a hydrolysis and condensation catalyst) to the silicon compounds to be hydrolyzed, either as such or dissolved in a suitable solvent, and the the resulting mixture is then stirred for some time (one to several hours).
• the hydrolysis is usually carried out at temperatures between -20 and 130 ° C, preferably between 0 and 30 ° C or the boiling point of the optionally used Solvent.
• the best way of adding water depends primarily on the reactivity of the starting compounds used.
• the dissolved starting compounds can be slowly added dropwise to an excess of water, or water can be added in one portion or in portions to the starting compounds, which may be dissolved. It may also be useful not to add the water as such, but to add it to the reaction system with the aid of water-containing organic or inorganic systems.
• the entry of the amount of water into the reaction mixture using moisture-laden adsorbents, for example molecular sieves, and water-containing organic solvents, for example 80% ethanol, has proven to be particularly suitable.
• the water can also be added via a chemical reaction in which water is released in the course of the reaction. Examples of this are esterifications.
• ketones preferably lower dialkyl ketones, such as acetone or methyl isobutyl ketone, ethers, preferably lower dialkyl ethers such as diethyl ether or dibutyl ether, THF, amides, esters, especially ethyl acetate , Dimethylformamide, amines, especially triethylamine, and mixtures thereof in question.
• the hydrolytic condensation is carried out without adding a solvent.
• the starting compounds do not necessarily all have to be present at the start of the hydrolysis (polycondensation), but in certain cases it can even prove advantageous if only some of these compounds are first brought into contact with water and the remaining compounds are added later.
• the water can be added all at once or in several stages, for example in three stages.
• the first stage for example, one tenth to one twentieth of the amount of water required for the hydrolysis can be added.
• a fifth to a tenth of the required amount of water can be added, and after a further brief stirring, the rest can finally be added.
• the condensation time depends on the respective starting components and their quantitative proportions, the catalyst used, the reaction temperature, etc. In general, the polycondensation is carried out under normal pressure, but it can also be carried out under increased or reduced pressure.
• the resin resulting after the condensation and when using a solvent after its removal can be removed by adding polymerization initiators such as e.g. of diethylenediamide or of hexahydrophthalic anhydride, harden at low temperatures by polymerization. If no polymerization initiators are added, the resin can be removed at elevated temperatures, e.g. harden at 180 ° C.
• polymerization initiators such as e.g. of diethylenediamide or of hexahydrophthalic anhydride
• the resins thus obtained are very suitable as adhesives for bonding inorganic substrates. If the resin is placed between two substrates, they are glued together in the course of the polymerization. Surprisingly, tensile forces of more than 5 MPa were measured when bonding silicon substrates or substrates with SiO 2 surfaces.
• the adhesives according to the invention have a high proportion of silanol groups, which surprisingly enable excellent bonding to inorganic substrate materials.
• the adhesive according to the invention is distinguished from the adhesives according to the prior art by an enormously improved adhesion to inorganic substrate materials.
• the bonded substrates are not only particularly firmly connected to one another, but also electrically insulated.
• no complex multilayer technology is required to produce the bonds according to the invention.
• the addition of one or more platinum and / or palladium complexes to the adhesive according to the invention further improves the already very good storage stability on the one hand and on the other hand to a further increase in the number of silanol groups and thus to an even better one Liability leads.
• the use of the platinum and / or palladium complexes stabilizes the silanol groups in the adhesive according to the invention. Improvements in storage stability and adhesion could already be achieved with a molar Si-OH: Pt or Pd ratio of 1:10 -6 .
• the platinum or palladium compounds are preferably added in the form of sols.
• sols for their production e.g. Solutions of Pt-IV compounds reduced with the following substances or with mixtures thereof: acetaldehyde, propionaldehyde, pyrocatechol, hydroquinone, pyrogallol, phloroglucin, gallic acid, tannin or protocatechic acid. It is preferred if the concentration of the Pt-IV solution is at least 0.0001 n and the concentration of the reducing agent is at least 0.001 n. The same applies to the use of palladium compounds.
• the adhesive according to the invention is extremely suitable for producing electrically insulating bonds in microelectronics or (micro) mechanics.
• the adhesive according to the invention can be used in optics, e.g. as an alternative for anodic bonding, for bonding protective glasses to solar cells or for bonding printed circuit boards to substrates for heat dissipation.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Silicon Polymers (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=7796784

Family Applications (1)

Country Status (3)

Cited By (1)

Family Cites Families (4)

• 1996
  • 1996-06-13 DE DE19623501A patent/DE19623501A1/de not_active Withdrawn
• 1997
  • 1997-06-06 EP EP97109169A patent/EP0812894B1/fr not_active Expired - Lifetime
  • 1997-06-06 AT AT97109169T patent/ATE199564T1/de active
  • 1997-06-06 DE DE59703089T patent/DE59703089D1/de not_active Expired - Lifetime

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